You rifle would be classified as a Half Stock Sporting Rifle or, possibly, a Plains Rifle. (Mainly determined by caliber.) The barrel marking may indicate where it was made or just where the barrel was made. Many of these half stocks were made by what I call "Winter Gunsmiths" (They would work the farm in the summer and supplement their income in the winter by building rifles.) Most of the parts could be ordered via mail (Barrel, lock and brass castings for the patch box, trigger guard and buttplate.) What the maker did was carving the stock and finishing the cast parts. Some built their own locks and or barrels. (I have examples of both.) Without a makers name, they are almost impossible to trace. A few were marked, most weren't. Many times a name found on the lock or barrel merely indicates the commercial source that part was ordered from. The half stock percussion types were made from around 1840 all the way up to the end of the percussion era around the turn of the century.
You might post your questions and pictures on The American Longrifle forum.